Our concern is with the relationship between theory (includig research) and practice in the area of social problems. Specifically, we propose (a) to construct an empirically based historical profile of the literature in several social problem areas, with primary emphasis on how the problems are defined; (b) to explore a number of factors affecting such problem definitions; and (c) to assess empirically interrelationships between theory and practice, primarily by analyzing the role of problem definitions contained in the scientific literature in affecting treatment orientations or ameliorative strategies selected to deal with the problem. As part of the third objective, which will assess the extent of utilization and application of the scientific literature in the treatment orientations, we will also explore the opposite relationship: the extent to which the scientific literature is influenced by the treatment/practice literature. The research will explore a wide range of factors both internal and external to the professions dealing with research on and treatment of each problem area, by means of a detailed and systematic analysis of the social problems literature. The proposed research will be both descriptive/exploratory (in the sense of charting a new area not previously studied empirically) and theroretical/hypothesis-testing, examining a number of propositions from such fields as knowledge utilization and the sociology of science. The proposed research will be helpful to both scientists and practitioners, in pointing up important implications and pitfalls that must be recognized and understood if the social sciences are to become relevant and useful in ways that are constructive and socially responsible.